Reversible airplane propeller



' .Sep't. 30, 1930. A. PETROW REVERSIBLE AIRPLANE PROPELLEH 2 Sheets-Sheet 1 Filed April 10, 1929 v INVENTOR. 41.:x PL'TR'OW BY Vs? ATTORNEYS.

Sept. 30, 1930. A. PETROW 1,776,980

REVERSIBLE AIRPLANE PROPELLER File'd April'lo, 1929 2 Sheets-Sheet -2 Lrx Psrmow ATTORNEYS.

Patented 30, 1930 UNITED srATEs PATENT OFFICE annx rn'rnow, or am fluncrsco, cannroama aavnasmnn alarms mrnrmn" Application filed AprlllO,

' I claimed.

An object of my invention-is to provide a reversible airplane progeller that may be controlled from the coc pit of an airplane while the propeller is rotating. The mechanism for swinging the blades into different angles is self-locking so as to holdthe blades against accidental movement after they have been swung into the desired position. The power for changing the angles of the blades is derived from the rotating propeller shaft.

A further object of my invention is to pro-; vide an indicating mechanism which will show at what angle the blades are positioned.

- The indicator'functions whilethe propeller is rotating.)

' Other 0 jects and advantages will appear as the specification proceeds, andthe novel features of the invention will be particularly pointed out in the appended claims. My invention is illustrated in the accompanying drawing,inwhich Figure 1 is a perspective view of the entire mechanism;

F Figure 2 is a section along the line 2-2 of so i 3; I

igure 3 is a section along the line 3-3 of Fi re 2;

igure 4 is Fi re 2; as igure 5 is Fi re 6; I

- igure 6 is a top plan view of Figure 5; and Figure 7 is a view showing a part of the indicating mechanism. I

'40. In carrying out my invention I make use of an engine crank shaft 1 (see Figure 3) that is rotated by an engine (not shown). The end of the shaft 1 has a square portion 2 and a threaded portion 3. A bullet-shaped casin or shell 4 has a square opening 5 for receiving the portion 2. The casing or shell 4 has a flange 6 that rides in a guide 7,-the

guide being secured to the airplane structure 8 b means. of screws 9 or other suitable fastemng means. -'A cap screw '10 is threaded a section along the line44 of a section along the line 5-4; of

1920. Serial at. 154,000.

into the portion 3 and aids in looking the shell 4 against longitudinal movement. It will be seen from this construction that a rotation of the shaft 1 will rotate the shell 4.

Airplane blades '11 have suitable shafts 12 5 that are journaled in the shell 4. the present drawing I have shown two blades. It is obvious that the number of blades may be increased if desired. The mechanism for turning each blade is identical, and there- '60 fore adescription of one will suflice.

The upper blade '11 in Figure 2 carries a worm gear 13. A worm 14 meshes with the gear 13 and is mounted upon a shaft 15 that also carries a bevel gear 16. The gear 16 meshes with a gear 17, and this latter gear is carried by a suitable shaft 18. A toothed wheel 19 is carried by the shaft 18 and is shown meshing with a large wheel 20 that has a ring of small openings 21 for receiving 7 the teethofthe wheel 19.

The large wheel 20 is connected by a sleeve 21 with a second large wheel 22 of similar design. Reference to Figure 3 shows that the sleeve 21 is slidably mounted upon the shaft 7 -1 and is held from rotation by guide pins 23 that in turn are carried by a bearing 24.

The large wheels 20 and 22 are held in neutral position with respect to the toothed wheels 19 by springs 25 and 26. In Figures 2 and 3 I have shown the wheels 20 and 22 moved to the right so as to mesh the wheel 20 with the toothed wheel 19.

The mechanism for moving the wheels 20 v and 22 is shownin Figures 1, 2 and 3. Bars 27 are secured to the wheel 22, andthese are slidably received in grooves 28 in the hearing 24. A lever 29' (see Fi crumed at 30 and has a-f0r ed and 31 the arms of which have slots 32 for receiving pins 33 carried bythe bars 27.

In Figure 1, I show the outer end of the lever .29 as being connected to a push-andull rod 34,.and I further show the. rod as ein operativelyconnected to a hand lever 35 p aced in the cockpit of the airplane. A sim le movement of the lever 35 forwardly, as s own in Figure 1, will cause the wheel 20 to engage with the toothed wheels 19.

A reverse movement of the lever 35'will l0.

bring the wheel 22 into engagement with the wheels 19..

I provide means for indicating the angle of the blades. A cam 36 is formed in the stub shaft 12 and will move a spring-pressed pin- 37 (see Figure 2). The pin has an outwardly-turned portion 38 that will wipe through a grooved member 39 of the shape shown in Figures 5 and 6. The portion 38 will move through the member 39 in the direction of the arrow (1 shown in Figure 6.

The member 39 is mounted upon a shaft 40 (see Figure 3) that is connected to a link 41 by means of an arm 42 (see Figure 1). The connection between the link 41 and an indicator 43 is shown in Figures 1 and 7 The indicator 43 has a. vertical shaft 44 that carries an arm 45 which is connected to the link 41.

The broken lines 46 and 47 show the two extreme paths through which the projection 38 moves. Figures 7 further shows how the member 39 is swung by the portion 38 as the portion passes between the upturned sides 48 of the member 39.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood.

. I have already set forth how the blades 11 may be swung into difi'erent an les by merely actuatin the hand lever 35. he worms 14 lock thelilades in adjusted position and prevent further movement until either the wheel 20 or the wheel 22 is brought into mesh with the wheels 19. The spring-pressed pin 37 is carried around with the shell 4 and is moved into difi'erent ositions by the cam 36. The

ortion 38 wi wipe through the member 39 or each revolution of the shell 4. This porv tion will swing the member 39 into a path that will permit the portion 38 to pass through the slot 49 formed by the ends of the sides 48 disposed nearest each other. The bearings supporting the member 39 and the shaft 40 provide enough friction to hold the portion in adzisted position. The movement of the memr 39 will be dependent upon the angle of the blades 11, and this movement will. be imarted to a needle 50 in the indicator 43 (see igure' 7), and this needle will move over a scale that will indicate the angle of the blades. In this way the ilot will know the position of the blades w e the propeller is functioning.

Although I have shown and described one embodiment of my invention, it is to be understood that the same is susceptible of various changes, and .I reserve the ri ht toemploy such changes as may come within the scope of the invention as claimed.

I claim:

1. A reversible airplane propeller compris ing a rotatable shaft, airplane blades secured to said shaft so as to rotate therewith, said blades being rotatable into diiferentangles, self-locking means for swinging the blades into the desired angle and including a toothed wheel for each lade, and non-rotatable wheels movable into operative engagement with the toothed wheels, said toothed wheels being rotated by the stationary wheels thereby swinging the blades in either direction into the desired angle.

2. reversible airplane propeller comprising a rotatable shaft, airplane blades secured to said shaft so as to rotate therewith, said blades being rotatable into different angles, self-locking means for swinging the blades into the desired angle and including a toothed Wheel for each blade, a non-rotatable wheel movable into operative engagement with the toothed wheels, said toothed wheels being rotated by the stationary wheel thereby swinging the blades into the desired angle, and a second non-rotatable wheel movable into operative engagement with said toothed wheels for causing the latter to rotate in an opposite direction.

3. A reversible airplane propeller comprising a rotating shaft, a shell carried by said shaft and being rotated therewith, radiallyextending propeller blades rotatably carried by said shell, self-locking means carried by said shell for rotating said blades in either direction, and manually-controlled means for operatively connecting said blade-rotating means with the shaft for swinging the blades into the'desired angles.

4. A reversible alrplane propeller comprising a rotating shaft, a shell carried thereby and rotatable therewit blades carried by said shell and extending radially from the shaft, means for swinging said blades about their longitudinal axes, said means including a toothed wheel for each blade, and non-rotatable wheels slidably mounted on said shaft and being movable into operative engagement with said wheels.

5. A reversible airplane propeller comprising a rotating shaft, a shell carried thereby and-rotatable, therewith, blades carried by said shell and extending radially from the shaft, means for swinging said blades about their longitudinal axes, said means including a toothed wheel for each blade, non-rotatable wheels slidably mounted on said shaft and being movable into operative engagement with said wheels, and s ring means for urging said non-rotatable w eels into neutral poand an indicatingmeans for showing the angle of the blades. 7. A reversible airplane propeller comprising a rotating shaft, a shell carried thereby 5 and rotatable therewith, blades carried by said shell and extending radially from the shaft, means for swinging said bladesabout their longitudinal axes, said means including a toothed wheel for each blade, non-rotatable 1 0 wheels slidably mounted on said shaft and being movable into operative engagement with said wheels, spring means for urging said non-rotatable wheels into neutral position, an indicating means for showing the angle of 15 the blades, said indicating means comprising a cam on one of the propellers, a springpressed finger riding on the cam, a member swingable by the varying positions occupied by the finger, and an indicating pointer'op'erw atively connected to said member for indicating the angle of the blades.

. a 8. A variable pitch propeller-comprising a shaft, a shell rotatable therewith, a plurality of blades rotatably carried by the shell,

25 a gear carried by each blade, a worm meshing with each gear, a pinion operatively connect- I ed with each worm, a pair of gears slidable 0n the shaft and held against rotation, said pair of gears normally straddling said pinions,

30 springs for yieldingly holding said gears out of mesh with said pinions, and manually controlled means'for moving either of said pair of gears into mesh with the pinions for swinging the blades into the desired angle.

a 9. A variable pitch propeller comprising a shaft, a shell rotatable therewith,'a plurality of blades rotatably carried by the shell, a gear carried by each blade, a worm meshing with I each gear, a pinion operatively connected 0 with each worm, a pair of gears slidable on the shaft and held against rotation, said pair of gears normally straddling said pinions, springs for yieldingly holding said gears out v of mesh with said pinions, normally controlled means for moving either of said pair of gears into mesh with the pinions for swinging the blades into the des redangle, and an in icating means for showing the angle of the blades. n 10. A reversible air lane ropeller comprising a-rotatingsha a s ell carried b said shaft and being rotated therewith, radia ly-extending ropeller blades rotatably carried by said s ell, self-locking means carried 7 M by said shell for rotating said blades in either direction, manually-controlled means for operatively connecting said blade-rotating means with the shaft for swinging the blades into the desired angles, and an indicating v M means for showing the an 1e of the blades.- w

' AL X PETROW. 

